The proposed project will clone cattle by fusion of adult fibroblasts with enucleated oocytes. The fused couplets will be placed in culture. The viable morulae will be transferred to recipient heifers to establish pregnancies. Since prior research suggests that the survival of fetuses cloned from adult cells will be low beyond 60 days gestation, we will remove several of these fetuses at 40 days gestation and establish fetal cell cultures. These fetal fibroblasts will be fused with enucleated oocytes. The morulae that result from this procedure will then be transferred to heifer recipients for the establishment of pregnancies. The survival of pregnancies beyond 60 days will be reported as successful results. As controls, in vitro derived blastomeres will serve as nuclear donor cells for nuclear transfer and the establishment of pregnancies. PROPOSED COMMERCIAL APPLICATIONS: This project will attempt to develop a reliable method of producing cloned calves from adult somatic cells of cattle.This technology will increase the efficiency of creating and multiplying very valuable transgenic cattle through improvements in the calving rate following adult cell cloning. Transgenic cattle produce therapeutic human proteins for treatment of congenital diseases much more efficiently and safely than current extraction procedures. Cell types and cell lines identified by Phase II will be marketed to the genetic engineering industry.